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Stage 7: Make the Chaser Move

Course progressStage 7 of 10
~70 min
One game, one Trinket

Keep building in the workspace on the right.

This stage is part of the same Crewmate Task Dash project you started in Setup. Type each new code block into the Trinket rail and keep building on the last stage.

Open Setup
Build

simple chase movement

Learn

how direction and timer loops create motion

Ship

a chaser that slowly follows the player

The big idea

The chaser does not need advanced AI. It can point toward the player, move forward a little, and repeat.

New words
timer loop
a function that asks Turtle to run again after a delay
towards
a Turtle method that finds the angle to a point or Turtle
heading
the direction a Turtle faces
AI
game logic that makes a computer-controlled actor seem smart
Finished game target
Tasks 2/4Score 80
Crewmate playerTask stationShadow chaser

The player moves through the ship, collects tasks, and avoids the chaser. All playable shapes are drawn with Python Turtle code.

Build it

Your turn

Type, run, test

Read the code aloud before you run it. The goal is to understand what changed in the game.
Need a hint?

Add the new code to the same Trinket project. Keep previous stage code unless the stage says to replace a function.

Python code task
Write this part

main.py

Add this to your current Trinket file.

game_on = True

def move_chaser():
    if not game_on:
        return
    chaser.setheading(chaser.towards(player))
    chaser.forward(4)
    draw_chaser()

def game_loop():
    check_tasks()
    move_chaser()
    screen.ontimer(game_loop, 80)

game_loop()
Trace it

Trace the idea

  1. `towards(player)` finds the angle to the player.
  2. `forward(4)` moves only a little each loop.
  3. `ontimer` keeps the loop running without blocking key presses.

Try this

Learning beat

Try this

Three short experiments. Predict before you run, then test your guess.

Predict first
Before running, predict which line will visibly change the screen first.
Compare
Change one number, run, then change it back. Which version feels more playable?
Connect
How does this stage make the final game more like a real project?

Test your stage

  • The chaser moves.
  • The chaser follows the player.
  • Arrow keys still work while the loop runs.